RESUMO
PURPOSE: To evaluate the reliability of the gyrB PCR-RFLP technique in differentiating clinical Mycobacterium tuberculosis complex isolates. MATERIALS AND METHODS: A primer pair MTUB-f and MTUB-r for M. tuberculosis complex (MTBC) was used to differentiate 79 mycobacterial isolates by specific amplification of the 1,020-bp fragment of the gyrB gene (gyrB-PCR1). The MTBC isolates were further differentiated using a set of specific primers MTUB-756-Gf and MTUB-1450-Cr that allowed selective amplification of the gyrB fragment specific for M. tuberculosis (gyrB-PCR2). The DNA polymorphisms in the 1,020-bp gyrB fragment for 7 M. tuberculosis strains confirmed by PCR as well as 2 reference strains; M. tuberculosis H37Rv and M. bovis BCG were analyzed with the restriction enzyme Rsa1. RESULTS: Seventy-seven (97.5%) isolates were positive for gyrB-PCR1 and thus identified as members of M. tuberculosis complex (MTBC) and two (2.6%) isolates were negative and identified as Mycobacteria other than tuberculosis (MOTT). All the M. tuberculosis isolates showed the typical M. tuberculosis specific Rsa1 RFLP patterns (100, 360, 560-bp) while 360 and 480-bp fragments were generated from M. bovis BCG. CONCLUSION: The gyrB PCR-RFLP using the endonuclease Rsa1 can be used to differentiate M. tuberculosis from M. bovis in clinical isolates.
Assuntos
Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana/métodos , Impressões Digitais de DNA/métodos , DNA Girase/genética , Mycobacterium tuberculosis/classificação , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , Primers do DNA/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Humanos , Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Polimorfismo Genético , Sensibilidade e Especificidade , Tuberculose/microbiologiaRESUMO
This paper reviews the literature on human leptospirosis in Malaysia from its first description in 1925 until the present day. Fletcher diagnosed the first case of human leptospirosis in Malaysia in 1925. Following Fletcher, many investigations on human leptospirosis in Malaysia disclosed a high prevalence of infection. These investigations indicated that the disease was endemic in the country. Examination of 1993 suspected human cases of leptospirosis by Tan indicated 28 % of the cases were positive. In a recent survey, 2190 serum samples from patients with different clinical manifestations in the country disclosed 12.6% were positive for antibodies to leptospires. The risk to leptospiral infection with respect to occupation, location, sex, race and age groups was demonstrated. Both civilians and military personnel were affected. Thirty-seven serovars from thirteen serogroups have been identified in the country. Recent studies on animal leptospirosis showed that the disease was highly endemic in the animal population. It is considered that the majority of leptospirosis cases in humans were due to association of man with animals and disease-infected environment.
